(Not Applicable)
The present invention generally relates to a system and a method for measuring a workpiece thickness, and more particularly to an improved system and method for measuring a workpiece thickness via an adjustable laser triangulation system that is operative to emit at least one laser beam in generally perpendicular relation to angularly oriented sides of the workpiece.
The concept of measuring workpiece thicknesses in commercial and military applications is well known. More specifically, the measuring of workpiece thicknesses may have wide variety of applications in the aerospace industry, substantially extending to all forms of structural and manufacturing related operations. For instance, a workpiece thickness measurement is frequently a required engineering specification in designing and manufacturing parts related to the field, namely, in construction and assembly of structures such as aircrafts or other forms of vehicles. Simply put, the workpiece thickness measurement is often a necessary product and design information. Thus, defining workpiece thickness measurements has become a vital and integral process in the aerospace industry, as well as other related industries.
In many industries, and in the aerospace industry in particular, the workpiece thickness measurement is usually obtained by a hands-on method. Such contention is generally true in obtaining thickness measurements for workpieces such as composite laminate skins. For example, when measuring thicknesses of composite laminate skins, many aerospace industries use traditional contact inspection methods.
As is generally known, the traditional contact inspection methods require the utilization of a plurality of tools (e.g., Micrometer, Vernier Caliper, Magna Mike). Moreover, an above average skill level personnel is oftentimes needed to operate such tools in order to measure the thicknesses of composite laminate skins. In other words, a certain level of personnel expertise may be demanded when determining thicknesses of composite laminate skins via the traditional contact inspection methods. Therefore, a significant cost associated with training the personnel may be unavoidable, as well as the time expended therewith.
However, even when the traditional contact inspection methods are applied correctly, such methods are marred by unfavorable limitations. For instance, the speed and accuracy of measuring the thicknesses of composite laminate skins are frequently compromised, as manual interaction plays a considerable role and is often inevitable. Furthermore, the tools utilized in the traditional contact inspection methods, such as the Micrometer and the Vernier Caliper, may generally be restricted to measuring static workpieces. As a result, such methods have posed to be moderately ineffective and inconvenient in the aerospace industry.
Many industries, not necessarily related to the aerospace industry, have begun using laser triangulation systems to measure thicknesses of desired workpieces. More specifically, the laser triangulation system may comprise two opposing laser heads, wherein a specific workpiece may be positioned therebetween. Thereafter, a laser beam may be radiated from each respective opposing laser heads on the surfaces of the workpiece. In addition, the opposing laser heads may further receive the laser beams which are reflected from the surfaces of the workpiece. The laser triangulation system may convert the laser beams into a computable signal for conveyance to a measurement device (i.e., a computer). Thus, the measurement device may then manifest the computable signal into a workpiece thickness measurement.
However, the laser triangulation systems have their disadvantages. In particular, it is imperative that the laser beams radiated from the laser heads be perpendicular to the surfaces of the workpiece. If they are not perpendicular to the workpiece surfaces, then the precision and accuracy of the thickness measurements may be substantially reduced. Moreover, both of the laser beams should be aimed at a common axis of the workpiece such that the precision and accuracy of the thickness measurements remain intact.
Continuing the above paragraph, the general preference to have the laser beams in perpendicular relation to the workpiece surfaces, while the laser beams are aimed at the common axis thereof, may be for the purposes of procuring the appropriate angles and depth. More specifically, acquiring the proper degrees of separation between the radiated laser beams and the reflected laser beams may be essential in the overall calculation of the workpiece thickness. Additionally, it may further be important that the laser beams share the common axis of the workpiece so that a measurement can be made as to the particular thickness of that axis.
The laser triangulation systems have generally been used to measure thicknesses of flat surfaced workpieces in the industries that they are most utilized in. Because of the flatness of the workpiece surfaces, a perpendicular relationship therewith may easily be achieved by the radiated laser beams. Moreover, the common axis of the workpiece may further be shared by the laser beams thereby. However, in certain industries, such as the aerospace industry in particular, the workpieces often do not possess flat surfaces. The aerospace industry usually involves construction and assembly of complex structures due to the inherent nature of its business. The workpieces involved in the aerospace industry may define sophisticated configurations and angular orientations. Application of the laser triangulation methods as described above may be difficult, and sometimes impractical. In order to obtain the desired perpendicular relationship and the common axis between the laser beams and the workpiece, the workpiece may need to be conformed to the laser triangulation system. Such tempering of the workpiece may result in incorrect measurement of its thickness.
Thus, there has long been a need in the industry, and in the aerospace industry in particular, for a uniform system and method of measuring workpiece thicknesses in a more efficient and accurate manner without involving highly skilled personnel. In particular, there is a need to apply such system and method to measure thicknesses of workpieces that define sophisticated configurations and angular orientations.
The present invention addresses the above-described deficiencies by introducing a system and a method to the aerospace industry in particular to avoid the traditional contact inspection methods when measuring workpiece thicknesses by utilizing a laser non-contact thickness measurement system. More specifically, the laser non-contact thickness measurement system is designed to conform to a plurality of workpiece configurations and angular orientations so as to facilitate the emission of laser beams in generally perpendicular relation thereto. In this respect, not only does the present invention mitigate the problems posed by the traditional contact inspection methods used in the aerospace industry, but it also corresponds to various workpiece configurations and angular orientations as well.
In accordance with a preferred embodiment of the present invention, there is provided a system and a method for measuring a thickness of a workpiece having first and second sides, wherein the second side may define a reference plane. The first side has a first angular orientation with respect to the reference plane. The reference plane may further define a target axis which extends perpendicular from a second side target point of the second side disposed in the reference plane through a first side target point of the first side.
A first laser triangulation emitter/sensor may be sized and configured to emit a first laser beam at the first side target point. More specifically, the first laser triangulation emitter/sensor may comprise a first laser diode for the purpose of emitting the first laser beam at the first side target point. The first laser triangulation emitter/sensor may further be receivable of a first array of diffused laser beams reflecting from the first side target point via a first lens and a first detector thereof. The first array of diffused laser beams may be reflectable from the first side target point to the first lens so as to focus upon the first detector therefrom.
The first detector may receive the first array of diffused laser beams from the first lens, wherein the first array of diffused laser beams may include a brightest diffused laser beam disposed therein. More particularly, the first detector may be operative to selectively detect the brightest diffused laser beam to generate a first signal in response to such detection.
In the preferred embodiment, there is further provided a first adjuster base engaged to the first laser triangulation emitter/sensor. The first adjuster base may be operative to adjust the first laser triangulation emitter/sensor to emit the first laser beam in generally perpendicular relation to the first angular orientation of the first side. Specifically, a first support column may be pivotally engaged to the first adjuster base. The first support column is engaged opposite the first laser triangulation emitter/sensor so as to position the first adjuster base therebetween. The first adjuster base may be pivotally movable with respect to the reference plane for facilitating adjustment of the first laser triangulation emitter/sensor. Moreover, a first support base may be removably engaged to the first support column, wherein the first support base is engaged opposite the first adjuster base so as to position the first support column therebetween. Thus, the first support column may be vertically adjustable, or movable, with respect to the reference plane for accommodating different thicknesses of the workpiece.
In addition, a second laser triangulation emitter/sensor may be sized and configured to emit a second laser beam at the second side target point. More specifically, the second laser triangulation emitter/sensor may comprise a second laser diode for the purpose of emitting the second laser beam at the second side target point. The workpiece may be placed between the first laser triangulation emitter/sensor and the second laser triangulation emitter/sensor. The workpiece may be a composite laminate skin.
In accordance with a preferred embodiment of the present invention, the second laser triangulation emitter/sensor may be receivable of a second array of diffused laser beams reflecting from the second side target point via a second lens and a second detector thereof. The second array of diffused laser beams may be reflectable from the second side target point to the second lens so as to focus upon the second detector therefrom.
The second detector may receive the second array of diffused laser beams from the second lens, wherein the second array of diffused laser beams may include a brightest diffused laser beam disposed therein. More particularly, the second detector may be operative to selectively detect the brightest diffused laser beam to generate a second signal in response to such detection.
Moreover, a second adjuster base may be engaged to the second laser triangulation emitter/sensor. The second side of the workpiece may further define a second angular orientation. The second adjuster base may be operative to adjust the second laser triangulation emitter/sensor to emit the second laser beam in generally perpendicular relation to the second angular orientation of the second side. Specifically, a second support column may be pivotally engaged to the second adjuster base. The second support column is engaged opposite the second laser triangulation emitter/sensor so as to position the second adjuster base therebetween. The second adjuster base may be pivotally movable with respect to the reference plane for facilitating adjustment of the second laser triangulation emitter/sensor. Moreover, a second support base may be removably engaged to the second support column, wherein the second support base is engaged opposite the second adjuster base so as to position the second support column therebetween. Thus, the second support column may be vertically adjustable, or movable, with respect to the reference plane for accommodating different thicknesses of the workpiece.
In the preferred embodiment, the first and second array of diffused laser beams may be respectively convertible into first and second signals for calculating the thickness of the workpiece along the target axis. More specifically, the first and second signals are respectively first and second electrical output signals. The first electrical output signal may be representative of a first distance between the first laser triangulation emitter/sensor and the first side of the workpiece. The second electrical output signal may be representative of a second distance between the second laser triangulation emitter/sensor and the second side of the workpiece.
Furthermore, the first and second distances may be respectively proportional to first and second angles. The first angle may be indicative of a degree of separation between the emitted first laser beam and the reflected first array of diffused laser beams. The second angle may be indicative of a degree of separation between the emitted second laser beam and the reflected second array of diffused laser beams. There may further comprise a measurement computer. The first and second electrical output signals may be transmittable to the measurement computer for calculating the thickness of the workpiece along the target axis.
Moreover, the workpiece may be maneuverable between the first and second laser triangulation emitters/sensors when they are stationary. More specifically, the first and second sides of the workpiece respectively define a plurality of corresponding first and second side target points. The first and second laser triangulation emitters/sensors may be operative to continuously emit the first and second laser beams at any of the plurality of corresponding first and second side target points.
In response, the first and second laser triangulation emitters/sensors receive the respective first and second array of diffused laser beams therefrom for measuring the thickness of the workpiece along each of the target axes defined thereby. The first and second array of diffused laser beams are continuously convertible into respective first and second electrical output signals as the workpiece maneuvers between the first and second laser triangulation emitters/sensors. Similar to above, the first and second electrical output signals are transmitted to the measurement computer to calculate the thickness of the workpiece along the respective target axes.
In particular, the workpiece has peripheral edges. The workpiece may be maneuvered such that none of the emitted first and second laser beams extend beyond the peripheral edges of the workpiece. In addition, the workpiece may be maneuverable in x, y, z and "THgr" axes with respect to the reference plane. More particularly, the workpiece may be laterally movable with respect to the reference plane along a x axis. The workpiece may be longitudinally movable with respect to the reference plane along a y axis. Furthermore, the workpiece may be vertically and rotationally movable with respect to the reference plane along a z and "THgr" axes, respectively.
The workpiece may define a configuration. The thickness of the configuration may be measured via emitting the first and second laser beams thereto when the workpiece is maneuvered between the first and second laser triangulation emitters/sensors. The configuration may be a pyramidal configuration that is defined in an intermediate area of the workpiece.